Electric wall fitting



Dec. 21, 1943. D. THOMSON ETAL ELECTRIC WALL FIT'I'ING Original FiledJan. 29. 191.11

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.a o n a Patentecl Dec. 21, 1943 ELECTRIC `WALL .FI'TING David Thomsonand David Thomson, Jr., Edinburgh, Scotland Original application January29, 1941, Serial No. 376,480. Divided and this application June 23,1941, Serial No. 399,260. In Great Britain February 8, 1940 8 Claims.

This invention which relates to subject-matter divided out of co-pendingapplication for Letters Patent Serial No. 376,480, 4filed January 29,1941, relates to electric couplings of the plugand-socket type as fittedto walls, skirting boards or other parts of b'uildings for enablingcurrent to be supplied to a plurality of current consumption apparatussuch as, for example, electric portable lamps, electric heaters,Velectric irons, or Wireless receiving apparatus.

The object of the present invention is to provide an improved electricWall fitting adapted for use in conjunction with a cable terminal oradapter having conductively-lined apertures adapted to be threaded uponthe pins of a plugand-socket coupling.

It is a further object of the invention to vprovide an electric wallfitting having the pins of the plug-and-socket coupling fixed inposition on the wall or other surface of the building and to enable acable terminal or adapter as afore- 'said or a plurality thereof to bereadily threaded upon the fixed pins.

A still further object of the invention is to provide an improved wallfitting comprising a combined electric wall switch and plug-andsocketcoupling, whereof the latter is adapted for use with a cable terminal oradapter having the characteristics aforesad.

The electric wall fitting forming the subject of the present inventionis especially adapted for use with the improved cable terminal oradapter forming the subject of our co-pending patent application SerialNo. 376,480 filed January 29, 1941.

According to our present invention a wall fitting secured or adapted tobe secured to the wall or other surface of a building is provided With adrawer slidable through anopening in the face plate of Vthe wallfitting, the said opening being in front of conducting pins secured inthe wall fitting, and the said drawer is provided internally with meansfor supporting one or more cable terminals or adapters of the Characteraforesaid in such a position that, When the drawer is inserted into thewall fitting, the terminals or adapters will be threaded upon the pinsof the wall fitting. Conversely, on withdrawing the drawer, theterminals or adapters are withdrawn with the drawer.

The wall fitting, which may be adapted to be accommodated in arecess inthe wall, may inorporate an electric switch, in which case the switchmay be connected to the conducting pins of the Wall fitting through amake-and-break contact, this contact being made by insertion of thedrawer and broken by wthdrawing the drawer, so that no current will besupplied to the conducting pins when the drawer is removed, even whenthe switch is in the "on position.

Other objects and advantages of the present invention Will appear onreference to the accompanying drawing whereon Figs. 1 and 2 illustratethe improved cable terminal or adapter forming the subject of ouraforesaid copending patent application and herein illustrated andvdescribed for the purpose of enabling our present invention to be morereadily understood.

In Fig. 1 the cable terminal or adapter is shown in perspective view,the cable leads theretol being shown in broken lines. Adjacent theadapter and also shown in broken lines isan'v ordinary plug member inperspective view. Fig. 2 shows the cable terminal or adapter of ourcopending patent application in cross-sectional View with parts of oneof the metallic linings separated from the adapter, and also shown in'broken lines in side view is an ordinary plug member.

Figs. 3, 4 and 5 illustrate an electric wall -fi'tting according to thepresent invention, Fig. 3, being a sectional plan view of the Wallfitting without the drawer, which is shown separately in sectional planview in Fig. 4-. Fig. 5 is a. perspective view of the drawer.

The terminal or adapter which is shown in full lines in Figs. l and 2and which forms the subject of our copending patent applicationcomprises a disc 3 of insulating material adaptedE for use with astandard electric plug member shown in broken lines at 4, the oneillustrated being a three-pin plug member having an earthing pin 5 andcurrent-conducting pins 6. The disc 3 has three apertures, each aperture'I having its ends enlarged to receive a ring 8 and the head 9 of atubular screw ll. The ring 8 is internally screw-threaded to fit theexternally screw-threaded hollow shank of the screw IO.. The disc 3 isformed internally with passagesl |2 which lead from the aperturesl tothe edge of the disc 3, so that the usual conducting leads 13 can bethreaded through the passages |2 and. can be conductively connected to,the` screw IO.

Referring now to Figs. 3, 4 and 5, the wall fitting there showncomprises a box 14 adaptd to be accommodated in a recess in the. wall,the skrting board of which is marked IB on the drawing. This box isclosed at the sides Ma and back Mb and part of the sides v14a of theboxare lned with insulating' material; 36. In-

serted into the box is a moulded insertion |8 of insulating material,secured to the back of the box |4 by screws 34. This insertion ismoulded to form a lining |8a for the sides IIIa of the box and apartition |8b which separates the front portion of the box into a drawercompartment |9 and a switch compartment 31. That part of the 'insertionI8 which forms the back of the compartment I9 supports a fixed plugmember which comprises a pair of conducting' pins IG and an earthing pin|'I of conventional' type. A removable face plate 20 is provided forclosing the front of the box l4 and this face plate has an opening in itfor the insertion of a drawer 2| shown in perspective in Fig. 5. Thedrawer 2| has internal Vertical ribs or guides 22 for supporting one ormore terminals or adapters I preferably of the form shown in Figs. 1 and2, the terminals or adapters being supported in a Vertical position inthe drawer 2| and in such a position that, when the drawer 2| isinserted into the compartment |9, the apertures in the terminals oradapters register with and slide upon the pins IB and Il. When thedrawer 2| is abstracted, the terminals or adapters move with the drawerand slide off the pins IB and I'I. The drawer 2| has an open top for theinsertion of the terminals or adapters which are held in spacedrelationship in the drawer by the internal Vertical ribs 22, and theback and bottom of the drawer are suitably apertured or cut away at 23to allow for the passage of the current leads or cables to the ends ofwhich the terminals or adapters I are fitted, these leads or cablespassing out through the front of the box M through an opening 24 in theface plate 20 below the drawer opening. The back of the drawer 2| isalso open or cut away to permit the pins I and I'I to pass into thedrawer and through the terminals or adapters therein when the drawer isclosed.

It is explained that the terminals or adapters I are connected to thefiexible leads or cables of current consuming apparatus such as portableelectric lamps, heaters, 'radio receiving sets or electric irons. InFig. 4 we have shown two adapters I inserted in the drawer 2|, eachbeingassumed to be connected to its own current consuming apparatus, forexample, one being connected to a radio-receiving set and the other to aportable electric lamp, so that, by inserting the adapters I in thedrawer 2| as shown in Fig. 4, and by inserting the drawer 2| in thecompartment |9 shown in Fig. 3, electric current may he supplied by thetwo pins |6 simultaneously to both a radio receiving set and a portablelamp, the current consuming apparatus being earthed through the pinsI'I. By withdrawing the drawer, and removing one of the adapters I','either the radio receiving set or the portable lamp can be disconnectedfrom the drawer 2|, since the opening 23 in the bottom and back of thedrawer allows the fiexible connections from the adapters I to the radioreceiving set or the portable lamp to pass out of the drawer 2|' whenthe adapter I is removed 'from the drawer. Obviously-the drawer 2| mayhave a sufiicient number of ribs 22 to receive and support three or moreadapters I if it is desired that the wall fitting shall be capable ofsupplying current to three or more current consuming devices.

The terminals or adapters I may be of such 'shape or outline that, whenthey are placed in the drawer, 2|, the apertures in the terminals oradapters will correctly register with the pins |6 and I'I and theterminals or adapters may be of such shape or outline that they will beprevented from turning out of register with the pins IG and I'I.

The wall fitting shown incorporates an electric switch 25 of anyconventional type mounted in the compartment 31 with the switch lever orhandle 26 protruding through a hole in the face plate 20. The maincurrent leads 21 and 28 to the wall fitting pass into the box I4 throughan opening in the back thereof and the switch 25 may be interposed inknown manner between the main current leads 21 and 28 and the pins I6,but we prefer to provide a make-and-break contact between the switch 25and the pins I 6 and for this purpose a two-part or divided socket 29 isfitted in the back of the compartment 19, one half of the socket 29being connected by a lead 30 to one of the pins IB and the other half ofthe socket 29 being connected by a lead 3| to one of the switch contacts32. The main leads 2'I and 28 pass one to the switch and the other toone of the pins IG as shown. The divided socket 29 is adapted to receivea contact pin 33 carried by the drawer 2|, the arrangement being suchthat, when the drawer is closed, the contact pin 33 completes theconnection between the leads 30 and 3| and when the drawer is pulled outcontact through the socket 29 is broken by withdrawal of the pin 33 fromthe socket 29. Consequently the switch is ineifective except when thedrawer 2| is in place in the box.

The moulded insertion I also serves as a base for the switch 25 which issecured in place by screws 35. The drawer 2| is preferably made ofinsulating material.

We claim:

1. An electric wall fitting comprising a casing having a drawercompartment therein open at the front, a drawer slidable in saidcompartment, conducting pins secured in said compartment to projecttowards the open front thereof, said drawer being so constructed thatsaid conducting pins will project into the interior thereof when saiddrawer is inserted into said compartment, and means in said drawer forpositioning therein an adapter having conductively-lined aperturesadapted to be threaded upon the said pins by insertion of the drawer,and to be withdrawn from the said pins when the drawer is opened.

2. An electric wall fitting comprising a casing having a drawercompartment therein open at the front, a drawer slidable into and out ofthe said compartment, a coupling plug member secured 'in said casingwith the pins of said plug member projecting into and towards the frontof said compartment and through an opening in the back of said drawer,means in said drawer for receiving and supporting a plurality ofadapters in spaced parallel relationship therein, and contact meansassociated with apertures in each of said adapters to engage the pins ofsaid plug member when the drawer is inserted and to be disengaged fromthe said pins when the drawer is opened.

3. In combination,V a casing having an open front, a drawer adapted toslide in said casing, electrical conducting pins secured in said casingto project towards the front thereof through an opening in the back ofthe drawer, Vertical guides on-the inner sides of said drawer, and aplurality of adapters receivable between said guides, each of saidadapters having conductively-lined apertures to enable said adapters tobe threaded upon the conducting pins when the drawer is closed, and saidguides efiecting the withdrawal of the adapters from said pins when thedrawer is opened.

4. An electric wall fitting comprising a casing open at the front, adrawer compartment in said casing, a switch mounted in said casing atone side of said compartment, a drawer slidable in said compartment,electrical plug pins secured in the rear of said compartment to projectforwards through an opening in the back of the drawer, means in saiddrawer for positioning therein an adapter adapted to be threaded uponthe'said pins when the drawer is inserted and to be withdrawn from thesaid pins when the drawer is opened, an electrical connection betweenone contact of the switch and one of the plug pins, a circuit-breaker insaid electrical connection, and a contact element on the drawer, saidcontact element being adapted to cooperate with the cii'- g cuit-breakerto complete the said electrical connection when the drawer is closed andto permit said circuit breaker to break the said electrical connectionwhen the drawer is pulled out.

5. An electric wall fitting comprising a casing open at the front, adrawer compartment in said casing, a switch mounted in said casing atone Iside of said compartment, a drawer slidable in said compartment,electrical plug pins secured in the rear of said compartment to projectforwards through an opening in the back of the drawer, means in saiddrawer for positioning therein an adapter adapted to be threaded uponthe said pins when the drawer is inserted and to be withdrawn from thesaid pins when the drawer is opened, an electrical connection betweenone contact of the switch and one of the plug pins, a divided socketsecured in the rear of said compartment and interposed in saidelectrical connection to break the said connection, and a contact p-inprojecting from the back of the drawer and adapted to enter said socketto complete the said electrical connection when the drawer is closed.

6. An electric wall fitting comprising a casing having an open front, aninsulator therein dividing said casing into a drawer compartment and aswitch compartment each open to the front of said casing, a drawerslidable in said drawer compartment, a switch mounted in the switchcompartment, a face plate closing the front of said casing and havingopenings in it for the drawer and the switch lever, electrical plug pinssecured in the rear of the drawer compartment to project through anopening in the back of the drawer, means in said drawer for positioningtherein an adapter having conductively-lined apertures adapted toregister with said pins, openings in the bottom of the drawer and in theface plate for the passage of electric cable leads connected to saidadapter, a circuit-breaker between one of said pins and one of theswitch contacts, and a contact element carried by the drawer and adaptedto cooperate with said circuit-breaker to complete the circuittherethrough When the drawer is closed and to break the said circuitwhen the drawer is opened.

7. An electric wall fitting comprising a casing having a drawercompartment therein open at the front, a drawer provided with internallydisposed positioning means and adapted to slidably fit into saidcompartment, conducting pins secured in said compartment projectingoutwardly toward the front thereof, said drawer being so constructedthat said conducting pins will project into the interior thereof whensaid drawer is inserted into said compartment, means for supplyingelectrical energy to said pins, and an adapter having a plurality ofconductively lined apertures adapted to be held in place by saidpositioning means, whereby said apertures will slide along andfrictionally engage said pins when and only when the drawer is movedinwardly toward the rear of said compartment.

8. An electric wall fitting comprising a casing having a drawercompartment therein open at the front, a drawer provided with internallydisposed positioning means and adapted to slidably fit into saidcompartment, conducting pins secured in said compartment and projectingout- Wardly toward the front thereof, said drawer being so constructedthat said conducting pins Will project into the interior thereof whensaid drawer is inserted into said compartment, means for supplyingelectrical energy to said pins, means including a, switch forcontrolling the supply of electrical energy to said pins, and an adapterhaving a plurality of conductively lined apertures adapted to be held inplace by said positioning means whereby said apertures will slide alongand frictionally engage said pins when and only When the drawer is movedinwardly toward the rear of said compartment.

DAVID THOMSON. DAVID THOMSON, JR.

